Hypothesis
A prediction to the outcome of the study
Independent variable
variable controlled by researcher
dependent variable
observed and measured by researcher
operational definition
a statement of the procedures (operations) used to define research variables. ( needs to be specific and measurable
Population
all the cases in a group being studied, from which samples may be drawn
random sample
every member of the population has an equal chance of being selected
random assignment
randomly sorting participants into two groups
experimental group
the group in an experiment that receives the variable being tested
control group
the group that does not receive the experimental treatment.
cofounding variable
in an experiment, a factor other than the independent variable that might produce an effect
illusory correlation
perception of a relationship where none exists, or perception of a stronger relationship than actually exists
Null hypothesis
Generally accepted belief you try to disprove
Expectation effects
Any changes in an experiment's results due to the subject anticipating certain outcomes to the experiment
Hawthorne Effect
A change in a subject's behavior caused simply by the awareness of being studied
researcher bias
researcher consciously or unconsciously behaves so as to make research outcome fit with their expectation
placebo effect
the phenomenon in which the expectations of the participants in a study can influence their behavior
blind procedures
participants are uninformed about what treatment, if any, they are receiving
double blind procedures
neither the participants nor the researchers know who has been assigned to the experimental or control group
survey
a data collection tool used to gather information about individuals
naturalistic
people are in normal environment and know they are not being watched
case study
gives in depth info about 1 person or small group
correlational study
a research project designed to discover the degree to which two variables are related to each other
experiment
A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process
longitudinal study
a study that observes the same participants on many occasions over a long period of time
cross sectional study
research that compares people of different ages at the same point in time (similar to longitudinal study but happens all at once)
meta-analysis
a "study of studies" that combines the findings of multiple studies to arrive at a conclusion
correlation coefficient
a statistical measure of the extent to which two factors vary together, and thus of how well either factor predicts the other
range
the difference between the highest and lowest scores in a distribution
measures of central tendency
mean, median, mode
statistically significant
refers to a result that is statistically unlikely to have occurred by chance
t-test
a statistical test used to evaluate the size and significance of the difference between two means
p-value
The probability level which forms basis for deciding if results are statistically significant (not due to chance).
Replication
repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances
standard deviation
a computed measure of how much scores vary around the mean score